Modern vehicles include internal combustion engines that can see hotter temperatures during operation. Cooling strategies for the internal combustion engine include directing a coolant, such as water, between a cylinder head and a cylinder block. One hot spot for the engine is the exhaust manifold. Some cooling strategies include an integrated exhaust manifold (or “IEM”). Implementation of an IEM allows for an exhaust port profile to be integrated and cast into the cylinder head. IEMs, however, place additional thermal loads on the cylinder head as IEMs require improved thermal boundary control to maintain desired temperatures. In past designs IEMs have been encased with a cooling jacket running against an upper and lower surface of the IEM. Still there is room for improved cooling strategies.
One possible option for improved cooling is to reverse flow direction through the engine. Reverse flow cooling designs, however, typically yield poorer overall coolant flow; misguided flow of coolant to areas of the cooling jacket; and slower coolant flow rates. The reverse flow cooling typically does not allow for metered coolant flow from an engine block since gasket holes in the head are not designed to direct coolant in two directions, i.e. to desired spots in the cylinder head and the block.
Therefore, it is desirable to have an improved cooling strategy for an IEM.